1. Field of the Invention
The present invention relates to a terminal input apparatus having a terminal data processing circuit connected to a central processing unit. More particularly, the present invention relates to a terminal input apparatus comprising a portable input device having an input key and a main device having a holder for the portable input device. Furthermore, the present invention relates to a connector suitable for use in this terminal input apparatus, and particularly, the present invention relates to a water-proof and dust-proof structure for a contact insertion hole in a connector utilizing mechanical connection between two contacts.
2. Description of the Related Art
As a means for precisely and promptly performing the management of sales of goods and the maintenance of stock, a vehicle-mounted terminal apparatus has been developed comprising a data processing device mounted on a goods-transporting truck for a sales network. Data, such as the kinds and quantities of goods are input according to customers requirements, and this data is processed by aggregation and editing. This terminal input apparatus has a portable input device having an input key and a connector in the lower portion and a main device having a holder for containing the portable input device, which is arranged on the front face of a casing. A data processing circuit is arranged in the main device having a holder for containing the portable input device, which is arranged on the front face of a casing. A data processing circuit is arranged in the main device and the holder has an insertion opening for the portable input device in the upper portion; and in the lower portion, has a main device side connector to be connected to a connector arranged in the lower portion of the portable input device.
Where this terminal input apparatus is mounted in a driver's cab of a goods-transporting truck, for reasons of space, the apparatus is attached to the side wall above the window on the driver's side. In this case, since the height of the ceiling of the driver's cab is limited, the space above the terminal input apparatus is very narrow and the operation of inserting the portable input device in the holder or extracting it therefrom is very difficult.
A connector for electrically connecting the portable input device to the main device should be disposed in the data processing apparatus comprising the portable input device and the main device provided with a data processing circuit, and a weak current (such as a signal current for transmitting data) and a large current (such as a power source current for driving electronic parts) transmitted through this connector. In this case, when the connection is for a weak current. Instead, a non-contact type light connection connector may be used to avoid abrasion and degradation of the contacts due to insertion and extraction of the connector. On the other hand, a light connection connector cannot be used for a large current such as a driving power current, and a mechanical contact type connection connector utilizing mechanical connection between contacts is used for such a large current. The conventional mechanical contact type connection connector has a structure in which a first connector (plug) is coupled to a second connector (jack), and a first contact (male contact) projected from the first connector is mechanically placed in contact with a second contact (female contact) arranged in the interior of an insertion hole of the second connector to electrically connect the first and second contacts.
If the conventional mechanical contact type connection connector is applied to the above-mentioned data processing apparatus, while the portable input device is being used when separated from the main device, the contact insertion hole of the connector is always open and, therefore, dust and water intrude into the connector through this insertion hole to cause problems such as contact failure.